The term “chemiluminescent reactant”, “chemiluminescently reactive” or “chemiluminescent reactant composition” is interpreted to mean a mixture or component thereof which will result in chemiluminescent light production when reacted with other necessary reactants in the processes as disclosed herein.
The term “fluorescent compound” is interpreted to mean a compound which fluoresces in a chemiluminescent reaction, or a compound which fluoresces in a chemiluminescent reaction.
The term “chemiluminescent composition” is interpreted to mean a mixture which will result in chemiluminescence.
The term “deagglomerate” is interpreted to mean to break up or loosen a compacted portion of a cluster or a mass.
The term “fluidizable solid admixture” is interpreted to mean a non-liquid admixture which behaves as a pseudo fluid when agitated, but has properties of a solid when at rest.
Chemiluminescent light production generally utilizes a two-component system to chemically generate light. Chemiluminescent light is produced by combining the two components, which are usually in the form of chemical solutions referred to as the “oxalate” component and the “activator” component. All suitable oxalate and activator compositions, inclusive of the various additional fluorescers, catalysts and the like, known to be useful in the prior art, are contemplated for use within the present invention.
The two components are kept physically separated prior to activation by a variety of means. Often, a sealed, frangible, glass vial containing one component is housed within an outer flexible container containing the other component. This outer container is sealed to contain both the second component and the filled, frangible vial. Forces created by intimate contact with the internal vial, e.g. by flexing, cause the vial to rupture, thereby releasing the first component, allowing the first and second components to mix and produce light. Since the objective of this type of device is to produce usable light output, the outer vessel is usually composed of a clear or translucent material, such as polyethylene or polypropylene, which permits the light produced by the chemiluminescent system to be transmitted through the vessel walls. These devices may be designed so as to transmit a variety of colors by either the addition of a dye or fluorescent compound to one or both of the chemiluminescent reactant compositions or to the vessel. Furthermore, the device may be modified so as to only transmit light from particularly chosen portions thereof.
Examples of such a chemiluminescent system include: U.S. Pat. No. 5,043,851 issued to Kaplan. Kaplan discloses a polygonal, chemiluminescent lighting device which concentrates light in the corners of the device, thus enhancing visibility of light emanating from the light stick portion of the device and optimizing the amount and distribution of light radiated.
U.S. Pat. No. 4,626,383 to Richter et al. discloses chemiluminescent catalysts in a method for producing light in short duration, high intensity systems, and low temperature systems. This invention relates to catalysts for two component chemiluminescent systems wherein one component is a hydrogen peroxide component and the other component is an oxalate ester-fluorescer component. Lithium carboxylic acid salt catalysts, such as lithium salicylate, which lower the activation energy of the reaction and also reduce the temperature dependence of the light emission process are taught.
U.S. Pat. No. 5,121,302 to Bay et al. describes a solid, thin, chemiluminescent device emitting light in one direction. The device is comprised of a back sheet of a laminated metal foil having heat sealed thereto at its edges a bi-component front sheet and a temporary separation means positioned to divide the interior area into two compartments. The bi-component includes a first component of which is a laminated metal foil and a second component of which is a transparent or translucent polyolefin sheet. The metal foil of the bi-component offers heat stability, increased shelf life, and relative impermeability to volatile components of the activator solution. The metal foil laminate for activator solution storage enables the activator solution to retain its viability due to the impermeability of the metal foil.
U.S. Pat. No. 6,062,380 to Dorney discloses a glow cup system with illumination capabilities. The apparatus is a generally cylindrically-shaped container made out of a semi-rigid material, with a preferred embodiment comprised of a translucent plastic material, to allow limited flexibility at the outer layer of the cup as its form can be somewhat altered temporarily by applying pressure to the sides. Within the side wall of the cup is a cavity. The cavity contains a plurality of rupturable ampoules containing a chemiluminescent fluid. The chemiluminescent fluid within the ampoule is an oxalate. A second chemiluminescent fluid resides within the cavity so that when the ampoule breaks open, the two fluids make contact and provide illumination. The ampoule is broken by applying pressure by the user on the outer layer of the cup at the cavity point. The bottom of the cup contains a plug, which may or may not be removable, which seals the second chemiluminescent component within the cavity spacing.
Additionally, it is desirable to produce chemiluminescent light from objects of various shapes or forms. U.S. Pat. No. 4,814,949 issued to Elliott discloses a means of making shaped, two-dimensional, chemiluminescent objects. Conventional liquid, chemiluminescent reagents are combined to produce light. A non-woven, absorbent article in the desired shape is permitted to absorb the chemiluminescent reagents after mixing and activation so that the article emits light from the shape desired. Although the shape may be as simple or as complex as desired, it is essentially limited to a two-dimensional surface and is additionally limited to producing a single color of light per device.
An example of creating a chemiluminescent system capable of producing light from a swellable polymeric composition is disclosed in U.S. Pat. No. 3,816,325 issued to Rauhut et al. Two primary means are employed to produce solid chemiluminescent systems. The first system relies on diffusion of a chemiluminescent oxalate solution into a solid polymer substrate such as a length of flexible vinyl tubing. The diffusion process occurs when a length of the vinyl tubing is immersed in a suitable chemiluminescent reagent for an extended period of time. After removal of the tubing from the oxalate solution, application of liquid activator to the surface of the tubing causes the tubing to emit light. Since the solid polymer is relatively non-porous, it is difficult to rapidly and completely activate the oxalate in the tubing because the relatively slow process of diffusion must also be relied upon to permit the activator solution to reach the chemiluminescent reagent diffused into the polymer before light can be generated.
In a further embodiment of U.S. Pat. No. 3,816,325, the chemiluminescent oxalate solution is mixed with a polyvinyl chloride (PVC) resin powder to form a paste, which is then spread on a substrate and baked in an oven to form a flexible, elastic film. While this embodiment is operative, the polyvinyl chloride sheet described exhibits weaknesses in uniformity, strength, flexibility, and most importantly, porosity. Additionally, the processes described are primarily suitable for producing relatively thin objects only.
U.S. Pat. No. 5,173,218 to Cohen et al. discloses a combination of PVC polymer resins to produce a porous, flexible, chemiluminescent structure from liquid slurries. Although an improvement in the art, the products produced still suffer from a variety of shortcomings, particularly if solid, chemiluminescent objects are to be produced which are other than relatively flat, thin objects. A thin “pad” is produced from a mixture of polymer resins, which is strong and flexible, and exhibits satisfactory absorptive properties of the activator fluid. However, the processes taught focus on producing pads which are made by pouring a liquid slurry mixture into molds. As such, the slurry and hence, the resulting pad shape, is limited to the shape of the mold, into which the slurry is poured and pools. Additionally, it is well-known to those skilled in the art that the formulas and processes utilized in the prior art may produce chemiluminescent pads with a relatively tough and impermeable “skin” wherever the slurry has been in contact with the mold during the baking process. This skin is easily recognized as a darker and more transparent region of the pad and is highly impermeable. Consequently, it is incapable of rapidly absorbing liquid activator solution and as such, minimally contributes to light output of the device. The thickness of this skin varies with the time and temperature of the baking process, but in any event, this skin represents wasted material from which little usable light may be produced. It has been determined that this skin is created by an inability of the slurry to draw in air (or other gasses) during the baking process. To achieve a significantly porous product, air must enter the slurry mixture during the baking process from the exposed surfaces of the slurry pool. During the curing process, air is usually drawn into the pad to replace the volume occupied by solvents which become absorbed into the PVC resins. This process continues as air is drawn down to ever increasing depths within the pad as first the upper regions of the pad cure and then successively lower regions of the pad cure. It is this inclusion of air into the pad during the baking process which primarily determines the percent of open pore space and hence absorptiveness of the pad. At some point during the baking process described, the bottom of the mold may reach a temperature at which the slurry mixture in contact with this region of the mold begins to jell and cure, even though an air path from the exposed surfaces of the slurry to this lower region may not have been created. Due to a lack of air available to this jelling slurry, this “bottom up” curing process results in a pad which is tough, dense, and virtually non-porous in the region of the pad proximal to the mold bottom and to a lesser extent, the mold edges. Certain adverse effects of this bottom up curing process can be minimized if the bottom of the mold is placed on a cold thermal mass in the curing oven, thereby providing for heating and curing of the bottom portion of the slurry following the remainder of the slurry. Nonetheless, the undesirable production of a tough and impermeable skin layer remains unaddressed.
During the baking processes, such as those disclosed in U.S. Pat. No. 5,173,218, the slurry expands as air is drawn into the polymer matrix, which air adds to the volume of the matrix. As a result, significant problems develop when attempting to cure a relatively large mass of this slurry. For example, if a liquid slurry mixture, as taught in the '218 patent, is poured into a test tube and baked for the appropriate time to cure, a dense, tough mass will be produced exhibiting very poor porosity and hence, poor absorbency throughout most of the mass. This is due in part to the “bottom up” curing process described above wherein insufficient air is drawn into the slurry during the curing process due to the existence of an air tight liquid layer above the slurry being cured near the mold bottom. Additionally, it has been unexpectedly found that the slurry materials will not draw in the requisite air if the slurry is inhibited from expanding during the curing process. In the case of the test tube example above, the side walls of the test tube constrain the slurry from expanding and drawing in the air required to produce a cured matrix with the high degree of porosity and absorbency required to permit activation of the product with liquid activator. Even though the slurry is free to expand vertically in the test tube during the curing process, the lateral constraint on the slurry by the walls of the test tube is sufficient to prevent optimal expansion of the slurry and air induction into the mass during the curing process. As such, the cured mass will exhibit low porosity and yield poor light output which is a limitation of the art.
It is often desirable to provide a chemiluminescent device which is not only capable of producing light, but producing light in a variety of colors. U.S. Pat. No. 5,508,893 issued to Nowak et al. is directed toward a multi-color chemiluminescent lighting device and method of producing the product. This device is comprised of a flexible tube filled at least partially with an activator solution, a plurality of ampoules containing oxalate solutions located within the tube, and at least one barrier element between ampoules to prevent color mixing. This device is capable of imparting different chemiluminescent colors following activation.
U.S. Pat. No. 5,705,103 issued to Chopdekar et al. describes a composition for producing chemiluminescent light of controllable duration. The composition is comprised of an oxalate component (including an oxalate ester) in a solvent, an activator component (a peroxide compound and a catalyst) in a solvent, and a fluorescer. By appropriate selection of the molecular weight of the homopolymer for the oxalate component, control of the total glow time and the point in time at which commencement of light production occurs may be varied. Although this device provides a controllable duration or stability of light, there is no suggestion of a composition to control the generation of gas produced or a composition which may be independent of a container, i.e. not formable or porous.
Thus, what is lacking in the art is a means for producing three-dimensional objects which are self-illuminated by means of chemiluminescence, and producing a highly porous composition to exhibit quick activation and excellent light output. In addition, the prior art fails to contemplate a product which may be independent of a container, minimizes dark areas due to gas generation, and which is capable of generating a plurality of spatially separated or wavelengths of chemiluminescent light simultaneously.